"While a globally warmed world is likely to produce greater crop yields"

I remember reading somewhere (sorry, can't remember exact source) that photosynthesis is less efficient above certain temperatures and that a change in the global average could cause some problems on that front.

is one of the most important investigations today.  This article, and many more like it, will shed new light on some things like the demise of the dino, perhaps even early man.

From the article:
A particularly disturbing study suggests that the mechanisms of CO2 nutrient depletion may already be causing a decline in the quality of our food supply. Josep Penuelas of the Center for Ecological Research and Forestry Applications in Barcelona, Spain, compared historical plant samples grown at preindustrial levels of atmospheric CO2 with modern equivalents. He found that today's plants had the lowest levels of calcium, copper, iron, potassium, magnesium, sodium, sulfur, and zinc than at any time in the last three centuries.

Isn't that interesting.  Remember that lightening discharges are one of the primary ways that the nitrogen in the earth is recharged. Sugar maples and other trees shed nitrogen rich leaves.  Tremendous volcanic activity in the past left the earth in a vaporous cloud of co2 for years.  Lots of questions.  So few answers.  

I certainly hope we will see more research on this topic.  Obviously, increased CO2 levels can have ramifications that we never even thought of.

"less nutritious plants ... will likely not be a problem for rich nations"

It's a problem when people in poorer nations just can't get enough food, of course. But even in the (quantitatively) well-fed nations, I think we are already suffering from lower nutrient content in our foods. If Scherer's scenario is right, we'll suffer progressively more with global warming.

When I'm stuck on the road and have to eat lower quality foods, I find it's hard not to eat too much. No matter how much mass market American food I eat, even if my belly is bulging, I still feel underfed. I have to consciously remind myself that good organic foods are waiting for me at home to avoid pigging out.

I think most people's bodies similarly feel, at some level, that there isn't a lot of food value in their food. If their minds don't know about nutritionally superior (organic, not overly fertilized) foods, they just have to eat more. Hence, the super-size thing. Hence, endemic obesity -- and its shadow, restrictive diets that leave rich women ironically malnourished.

I'm saying that poor nutritional quality of mass market foods may already be a cause of disease in the First World.

Because eating is the most constant, basic enactment of our need to consume things, there may be a connection with the culture of greed as well. If people's bodies never feel well fed, then at a basic bodily level they can never be satisfied with what they have ...